DE102012217968A1 - tire - Google Patents

Abstract

A pneumatic tire 1A having a plurality of major circumferential grooves 21 to 23 extending in the tire circumferential direction and a plurality of land portions 31 to 34 divided and formed by these major circumferential grooves 21 to 23 in a tread portion will be described. In addition, the plurality of web portions 31 to 34 has a plurality of blades 312 to 342, respectively. Further, not less than 90% of the sipes 312 and 322 arranged in an inner side area consisting of two-dimensional sipes and not less than 90% of the sipes 332 and 342 arranged in an outer side area are composed of three-dimensional sipes. In addition, the tread portion has an upper rubber 151 and a lower rubber 152. A rubber hardness H1_in at -10 ° C and a rubber hardness H2_in at 20 ° C of the top rubber 151_in in the inside area and a rubber hardness H1_out at -10 ° C and a rubber hardness H2_out at 20 ° C of the top rubber 151_out in the outside area have such relationships. that H1_in <H1_out and H2_in <H2_out.

Description

Technical area

The present invention relates to a pneumatic tire, and more particularly relates to a pneumatic tire with which both dry steering stability and steering stability on snow can be achieved.

Background of the invention

In a typical winter tire, a tread portion has fins to improve the steering stability of the tire on snow. The technology described in Patent Document 1 is known as a prior art pneumatic tire configured in this manner. In prior art pneumatic tires, compared to the tread portion on a vehicle mounting outside, the tread portion on a vehicle mounting inner side is formed of a softer rubber and also has a smaller fin density.

Documents of the prior art

• Patent Document 1: Untested Japanese Patent Application Publication No. 2010-6108A

Brief description of the invention

Problem to be solved by the invention:

In winter tires, there is a need to improve not only the steering stability on snow but also the dry steering stability.

In view of the foregoing, an object of the present invention is to provide a pneumatic tire capable of achieving both dry steering stability and steering stability on snow.

Means of solving the problem:

In order to achieve the above-described object, a pneumatic tire of the present invention has a plurality of circumferential main grooves in the tire circumferential direction and a plurality of land portions divided and formed by the circumferential main grooves in a tread portion. In such a pneumatic tire, an area corresponding to 35% of a straightened width of a tread pattern from a first tread edge is called an inner side area, and an area corresponding to 35% of a straightened width of a tread pattern from a second tread edge is called an outer side area. The plurality of land portions each have a plurality of sipes, and not less than 90% of the sipes arranged in the inner side region are composed of two-dimensional sipes, and not less than 90% of the sipes arranged in the outer side region consist of three-dimensional sipes. The tread portion has an upper rubber and a lower rubber and a rubber hardness H1_in at -10 ° C and a rubber hardness H2_in at 20 ° C of the upper rubber in the inside area and a rubber hardness H1_out at -10 ° C and a rubber hardness H2_out at 20 ° C of the upper rubber in the outer side area have such relationships that H1_in <H1_out and H2_in <H2_out.

In addition, a pneumatic tire according to the present invention has a plurality of circumferential main grooves in the tire circumferential direction and a plurality of land portions divided and formed by the circumferential main grooves in a tread portion. In such a pneumatic tire, an area corresponding to 35% of a straightened width of a tread pattern from a first tread edge is called an inner side area, and an area corresponding to 35% of a straightened width of a tread pattern from a second tread edge is called an outer side area. The plurality of land portions each have a plurality of sipes, and not less than 90% of the sipes arranged in the inner side region are composed of three-dimensional sipes, and not less than 90% of the sipes arranged in the outer side region consist of two-dimensional sipes. The tread portion has an upper rubber and a lower rubber and a rubber hardness H1_in * at -10 ° C and a rubber hardness H2_in * at 20 ° C of the upper rubber in the inside area and a rubber hardness H1_out * at -10 ° C and a rubber hardness H2_out * at 20 ° C of the top rubber in the outside area, such relationships are H1_in *> H1_out * and H2_in *> H2_out *.

Effect of the invention:

In the pneumatic tire according to the present invention, two-dimensional fins are arranged in the inner side region and three-dimensional fins are arranged in the outer side region. Therefore, the rigidity in the inside area is set low and the rigidity in the outside area is set high. In addition, the rubber hardnesses H1_in and H2_in in the inner side region and the rubber hardnesses H1_out and H2_out in the outer side region have such relationships that H1_in <H1_out and H2_in <H2_out. Therefore, the rigidity in the inner side area is set low, and the rigidity in the Outside area is set high. Thus, there is a synergistic decrease in inside-side stiffness and a synergistic increase in outside-side stiffness. As a result, when the pneumatic tire is mounted on a vehicle such that the inner side portion is on an inner side in the vehicle width direction, the inner side portion greatly contributes to improving the steering stability on snow, and the outer side portion greatly contributes to improving the dry steering stability. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are largely achieved.

In addition, in the pneumatic tire according to the present invention, three-dimensional fins are arranged in the inner side region and two-dimensional fins are arranged in the outer side region. Therefore, the rigidity in the inside area is set high, and the rigidity in the outside area is set low. In addition, the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * in the outside area have such relationships that H1_in *> H1_out * and H2_in *> H2_out *. Therefore, the rigidity in the inside area is set high, and the rigidity in the outside area is set low. Thus, there is a synergistic increase in inside-side stiffness and a synergistic decrease in outside-side stiffness. As a result, when wearing a pneumatic tire 1B is mounted on a vehicle such that the inner side portion is located on an inner side in the vehicle width direction, the inner side portion greatly contributes to improving the dry steering stability, and the outer side portion greatly contributes to improving the steering stability on snow. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are largely achieved.

Brief description of the drawings

1 FIG. 10 is a cross-sectional view in the tire meridian direction illustrating a pneumatic tire according to Embodiment 1 (Embodiment 2) of the present invention. FIG.

2 FIG. 11 is a plan view illustrating a tread surface of the in. FIG 1 illustrated pneumatic tire illustrated.

3 Fig. 4 is an explanatory drawing showing an example of a three-dimensional fin.

4 Fig. 4 is an explanatory drawing showing an example of a three-dimensional fin.

5 FIG. 11 is an explanatory view showing Modification Example 1 (Modification Example 3) of FIG 1 represents illustrated pneumatic tire.

6 FIG. 11 is an explanatory view showing a modification example 2 (modification example 4) of the present invention. FIG 1 represents illustrated pneumatic tire.

7 FIG. 11 is an explanatory view showing a modification example 5 of the embodiment of FIG 1 represents illustrated pneumatic tire.

8th FIG. 14 is a table showing the performance test results of pneumatic tires according to Embodiment 1 of the present invention. FIG.

9 FIG. 12 is a table showing the performance test results of pneumatic tires according to Embodiment 2 of the present invention.

Best way to carry out the invention

The present invention will be described below in detail with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, components of the embodiment that may or may be exchanged while preserving accordance with the present invention are included. Furthermore, a variety of modified examples described in the embodiment may be freely combined within a range obvious to a person skilled in the art.

A pneumatic tire of Embodiment 1

1 FIG. 12 is a cross-sectional view in the tire meridian direction illustrating a pneumatic tire according to an embodiment of the present invention. FIG. 2 FIG. 11 is a plan view illustrating a tread surface of the in. FIG 1 illustrated pneumatic tire illustrated. In these drawings, a radial tire is shown for use on a passenger car. It should be noted that the upper tread rubber in 1 hatched is shown.

A pneumatic tire 1A has a pair of tire bead cores 11 . 11 , a pair of tire bead filler 12 . 12 , a carcass layer 13 , a belt layer 14 , Tread rubber 15 and a pair of sidewall rubbers 16 . 16 (please refer 1 ) on. The pair of tire bead cores 11 . 11 has annular structures and represents cores of the left and right tire bead portions. The pair of bead fillers 12 . 12 is on a perimeter of each of the pair of tire bead cores 11 . 11 arranged in the tire radial direction so that it reinforces the Reifenwulstabschnitte. The carcass layer 13 has a single-layered structure and extends annularly between the left and right bead cores 11 and 11 Making a frame for the tire. In addition, both ends of the carcass layer 13 so folded to an outside in the tire width direction that they are the bead cores 11 and the tire bead fillers 12 envelop, and fix. The belt layer 14 is made of a pair of belt layers 141 and 142 which are laminated, formed and in the tire radial direction on a circumference of the carcass layer 13 arranged. These belt layers 141 and 142 are formed by arranging and rolling a plurality of belt cords made of steel fiber material or organic fiber material. A diagonal structure is achieved by arranging the belt cords so as to incline in mutually different directions with respect to the tire circumferential direction. The tread rubber 15 is at the periphery of the carcass layer 13 and the belt layer 14 arranged in the tire radial direction and forms a tire tread. The pair of sidewall rubbers 16 . 16 is on every outside of the carcass layer 13 in the tire width direction so as to form left and right side wall portions of the tire.

In addition, the pneumatic tire points 1A a plurality of main circumferential grooves 21 to 23 extending in the tire circumferential direction and a plurality of land portions 31 to 34 coming from the main circumferential grooves 21 to 23 divided and formed in the tread portion on (see 2 ). It should be noted that "main circumferential grooves" refers to circumferential grooves having a groove width of 3 [mm] or more. In addition, the web sections 31 to 34 Be rows of blocks (see 2 ) or they may be ribs (not shown).

An area corresponding to 35% of a straightened width of a tread pattern PDW from a first tread edge is referred to as an "inner side area". An area corresponding to 35% of a straightened width of a tread pattern PDW from a second tread edge is called an "outside area". It should be noted that differences in the configurations of the inside area and the outside area will be described later. The straightened width of the tread pattern PDW in a straightened drawing is the linear distance between the two edges of the tread pattern portion of the standard rim-mounted tire to which a standard internal pressure and no load are applied.

Besides, the pneumatic tire has 1A a display indicating the mounting direction (not shown) on a vehicle, wherein the inside area is on an inside in the vehicle width direction. The indication of the mounting direction of the tire may be indicated by marks or depressions and protrusions provided in the sidewall portion of the tire.

For example, in the configuration of 2 the pneumatic tire 1A a left-right symmetric tread pattern. The pneumatic tire 1A also has three of the main circumferential grooves 21 to 23 on. In addition, the middle main circumferential groove 22 arranged on a tire equatorial plane CL. Furthermore, two middle web sections 32 and 33 and a pair of left and right shoulder land sections 31 and 34 from these main circumferential grooves 21 to 23 assigned. Here are the three main circumferential grooves 21 to 23 and the four bridge sections 31 to 34 from the inside in the vehicle width direction to the outside in the vehicle width direction as a first land portion 31 , first main circumferential groove 21 , second bridge section 32 , second main circumferential groove 22 , third bridge section 33 , third main circumferential groove 23 and fourth bridge section 34 designated.

In addition, each of the web sections 31 to 34 a plurality of lug grooves 311 until respectively 341 that run in the tire width direction. These lug grooves 311 to 341 are arranged at a predetermined pitch in the tire circumferential direction. Furthermore, the lug grooves 321 of the second land section 32 and the lug grooves 331 the third bridge section 33 each open structure on and traverse the second bridge section 32 or the third bridge section 33 in the tire width direction so as to be open to the left and right edges thereof, respectively. As a result, the second land portion 32 and the third bridge section 33 divided in the tire circumferential direction and a series of blocks is formed. On the other hand, the lug grooves 311 of the first bridge section 31 and the lug grooves 341 the fourth bridge section 34 a half-closed structure and have an end portion that is open to the edge on the outside in the tire width direction, and an end portion that terminates on the inside in the tire width direction within the web portions on. Thus, the first web section 31 and the fourth bridge section 34 a rib that is continuous in the tire circumferential direction.

Slat configuration and rubber hardness

At the pneumatic tire 1A points each of the web sections 31 to 34 a plurality of fins 312 until respectively 342 on (see 2 ). Furthermore, not less than 90% of the fins exist 312 and 322 , which are arranged in the inside area, of two-dimensional slats and not less than 90% of the slats 332 and 342 , which are arranged in the outer side area, consist of three-dimensional slats.

Here, "lamellae" refers to incisions formed in a web section. "Two-dimensional slats" refers to slats having a slat wall surface with a linear shape (when viewed as a cross section from a direction perpendicular to a slat length direction). "Three-dimensional sipes" refers to sipes having a sipe wall surface having a shape that is curved in the sipe width direction (when viewed as a cross section from a direction perpendicular to the sipe length direction). Compared to the two-dimensional slats, the three-dimensional slats have a greater engagement force between opposing slat wall surfaces and therefore act as reinforcement for the rigidity of the web sections.

For example, in the configuration of 2 the first bridge section 31 , the second bridge section 32 , the third bridge section 33 and the fourth bridge section 34 each of the plurality of slats 312 to 342 on. In addition, the slats 312 to 342 a straight shape extending in the tire width direction, and are respectively arranged parallel to each other in the tire circumferential direction and at a predetermined pitch. Furthermore, the slats 312 to 342 a closed structure, each within the web sections 31 to 34 ending. In addition, the slats 312 of the first bridge section 31 and the slats 322 of the second land section 32 two-dimensional slats, and the slats 332 of the third bridge section 33 and the slats 342 of the fourth bridge section 34 are each three-dimensional slats. Thus, due to a difference in rigidity between the two-dimensional slats 312 and 322 and the three-dimensional lamellae 332 and 342 the rigidity of the first web section 31 and the second land portion 32 set on the inside in the vehicle width direction, set low and the rigidity of the third land portion 33 and the fourth bridge section 34 that are arranged on the outside in the vehicle width direction is set high.

In addition, in the pneumatic tire 1A the tread portion is an upper rubber 151 and a lower rubber 152 on (see 1 ). A rubber hardness H1_in at -10 ° C and a rubber hardness H2_in at 20 ° C of the upper rubber 151_in in the inside area and a rubber hardness H1_out at -10 ° C and a rubber hardness H2_out at 20 ° C of the upper rubber 151_out in the outer side area, such relationships are H1_in <H1_out and H2_in <H2_out.

Here, "rubber hardness" refers to a JIS A hardness according to JIS K6263 , In cases where the upper rubber or the lower rubber is formed in a predetermined area (the central area or the shoulder areas) of a plurality of rubber materials, the rubber hardness is calculated as the average rubber hardness by the following formula (1). In formula (1), Sk is a cross-sectional area of each of the rubber materials in a tire meridian sectional view, Hk is the rubber hardness of each of the rubber materials, and Sa is a cross-sectional area of the predetermined area in a tire meridian cross-sectional view. Rubber hardness H = (ΣSk × Hk) / Sa (where k: 1, 2, 3, ..., n) (1)

For example, in the configuration of 1 the upper rubber 151 from an upper inside rubber 151_in and an upper outside rubber 151_out educated. The upper inside rubber 151_in is disposed in an inner side region and the upper outer side rubber 151_out is arranged in an outside area. There is a boundary between the upper inside rubber 151_in and the upper outside rubber 151_out under a groove bottom of the second circumferential main groove 22 which is disposed on the tire equatorial plane CL. The rubber hardnesses H1_in and H2_in of the upper inside rubber 151_in and the rubber hardnesses H1_out and H2_out of the upper outside rubber 151_out have such relationships that H1_in <H1_out and H2_in <H2_out. Thus, due to a rubber hardness difference, the upper rubbers become 151_in and 151_out the rigidity of the first web section 31 and the second land portion 32 set in the inner side area, set low and the rigidity of the third land portion 33 and the fourth bridge section 34 which are located in the outer side area is set high.

At the pneumatic tire 1A are the two-dimensional slats 312 arranged in the inner side area, and the three-dimensional slats 332 are arranged in the outer side area. Therefore, the rigidity in the inside area is set low and the rigidity in the outside area is set high (see 1 and 2 ). In addition, the rubber hardnesses H1_in and H2_in in the inner side region and the rubber hardnesses H1_out and H2_out in the outer side region have such relationships that H1_in <H1_out and H2_in <H2_out. Therefore, the rigidity in the inside area is set low and the rigidity in the outside area is set high. Thus, there is a synergistic decrease in inside-side stiffness and a synergistic increase in outside-side stiffness. As a result, when wearing the pneumatic tire 1A mounted on a vehicle so that the inside area is on an inside in the vehicle width direction, the inner side area greatly contributes to improving the steering stability on snow, and the outer side area greatly contributes to the improvement of dry steering stability. As a result, both dry steering stability and steering stability of the tire on snow are achieved to a high degree.

It should be noted that the configuration of 1 a border between the upper inside rubber 151_in and the upper outside rubber 151_out under a groove bottom of the second circumferential main groove 22 located in the tire equatorial plane CL is located. However, the configuration is not limited to this and the boundary between the upper inside rubber 151_in and the upper outside rubber 151_out may be at a position other than that under the groove bottom of the second circumferential main groove 22 be arranged (not shown). In such a configuration, the rubber hardnesses H1_in and H2_in of the upper rubber of the inner side portion and the rubber hardnesses H1_out and H2_out of the upper rubber of the outer side portion are calculated according to the above-described formula (1).

3 and 4 are explanatory diagrams illustrating examples of the three-dimensional lamella. These drawings are perspective views of a wall surface of the three-dimensional sipe.

At the three-dimensional lamella of 3 For example, the lamella wall surface has a structure in which pyramids and inverted pyramids are connected in lamella length direction. In other words, the sipe wall surface is formed by mutually offsetting the pitch of a tread surface of the tread surface side and a zigzag shape of the bottom side in the tire width direction so that opposite projections and recesses are formed between the tread surface side and bottom side zigzag shapes. In addition, in these protrusions and depressions when viewed in the tire rotation direction, the sipe wall surface is formed by bonding a protrusion bending point on the tread surface side with a depression bending point on the bottom side, a depression bending point on the tread surface side with a protrusion bending point on the bottom side, and protrusion bending points respectively on the protrusion bending point on the tread surface side and adjoin the protrusion bending point at the bottom side, formed with ridgelines and joining these ridgelines with successive planes in the tire width direction. In addition, a first surface of the fin wall surface has a corrugated surface with convex pyramids and inverted pyramids thereof alternately arranged in the tire width direction, and a second surface of the fin wall surface has a corrugated surface with concave pyramids and inverted pyramids thereof alternately arranged in the tire width direction. In addition, in the fin panel, at least the corrugated surfaces disposed on outermost sides of both ends of the fin are directed toward an outside of the blocks. It should be noted that examples of such a three-dimensional lamella are those in the Japanese Patent No. 3894743 described technology belongs.

In addition, points at the three-dimensional lamella of 4 the sipe wall surface has a structure in which a plurality of prism shapes having a block shape are connected in the sipe depth direction and sipe length direction while being inclined with respect to the sley depth direction. In other words, the louver wall surface has a zigzag shape in the tread surface. In addition, the sipe wall surface has bent portions at at least two locations in the tire radial direction in the blocks that are bent in the tire circumferential direction and connected to each other in the tire width direction. Further, these bent portions have a zigzag shape that oscillates in the tire radial direction. Further, in the louver wall surface, the oscillation in the tire circumferential direction is constant, an inclination angle in the tire circumferential direction with respect to a normal direction of the tread surface is configured to be smaller at the part of the fin bottom than at the part of the tread surface side, and the oscillation in the tire radial direction of the bent one Section is configured to be larger at the part of the sipe bottom side than at the part of the tread surface side. It should be noted that examples of such a three-dimensional lamella are those in the Japanese Patent No. 4316452 described technology.

At the pneumatic tire 1A For example, the rubber hardnesses H1_in and H2_in in the inner side region and the rubber hardnesses H1_out and H2_out in the outer side region preferably satisfy the conditions: 65 ≦ H1_in ≦ 75, 62 ≦ H2_in ≦ 72, 68 ≦ H1_out ≦ 78 and 65 ≦ H2_out ≦ 75, and 3 ≦ H1_out-H1_in ≦ 10 and 3 ≦ H2_out - H2_in ≦ 10. As a result, the relationship between the rubber hardnesses H1_in and H2_in in the inside area and the rubber hardnesses H1_out and H2_out in the outside area is set appropriately.

In addition, in the pneumatic tire 1A a sipe density D_in of the inner side region and a sipe density D_out of the outer side region preferably have a relationship such that 1.2 ≦ D_in / D_out ≦ 2.0 (not shown). That is, the The sipe density D_in of the inner side portion is preferably larger than the sipe density D_out of the outer side portion.

Here, "lamella density" refers to a ratio of lamella length to the ground contact surface of a land portion. The slat length increases because, for example, the slats are provided with a curved shape. In addition, the sipe density can be easily adjusted by, for example, adjusting the sipe length, the number of sipes, and the like.

As described above, in the pneumatic tire 1A due to the arrangement of the two-dimensional slats 312 and 322 and the three-dimensional lamellae 332 and 342 and the rubber hardness difference between the upper rubber 151_in in the inside area and the upper rubber 151_out in the outer side, the rigidity of the web sections 31 and 32 the inside area is set low and the rigidity of the land sections 33 and 34 of the outside area set high. Thus, by providing the difference between the disk densities D_in and D_out as described above, the rigidity of the land portions 31 and 32 the inner side area are set even lower and the rigidity of the web sections 33 and 34 the outside area can be set even higher.

In addition, in the pneumatic tire 1A a groove area ratio S_in of the inner side area and a groove area ratio S_out of the outer side area in a ground contact patch of the tire preferably have a relationship such that 1.2 ≦ S_in / S_out ≦ 2.0, and a total groove area ratio S_t in the ground contact piece of the tire is preferably within a range of 0 , 25 ≤ S_t ≤ 0.38 (see 2 ). As a result, the ratio S_in / S_out of the groove area ratio S_in of the inside area to the groove area ratio S_out of the outside area, and the total groove area ratio S_t are set appropriately.

Here, "groove area ratio" is defined as groove area / (groove area + ground contact area). "Groove area" refers to the opening area of the grooves in the footprint. "Groove" refers to the circumferential grooves and lug grooves in the tread portion and not to fins and notches. "Ground Contact Area" refers to the contact area between the tire and the footprint. It is to be noted that the groove area and the ground contact area are measured at a contact surface between a tire and a flat plate in a configuration in which the tire is mounted on a standard rim, inflated to a prescribed internal pressure with respect to the flat plate perpendicular to a static condition and loaded with a load corresponding to a prescribed load. It should be noted that the ground contact patch of the tire refers to a contact surface between a tire and a flat plate in a configuration in which the tire is mounted on a standard rim, inflated to a prescribed internal pressure with respect to the flat plate perpendicular to one static condition and loaded with a load corresponding to a prescribed load.

Here, "standard rim" refers to a "standard rim", as defined by the Japan Automobile Tire Manufacturers Association (JATMA), a "design rim", defined by the Tire and Rim Association (TRA, Tire and rim dressing), or a "measuring rim", defined by the European Tire and Rim Technical Organization (ETRTO, European Tire and Wheel Welding Organization). In addition, "prescribed internal pressure" refers to "maximum air pressure" as defined by JATMA, the maximum in "tire load limits at various cold inflation pressures" as defined by TRA or the "inflation pressures "as defined by ETRTO. In addition, "prescribed load" refers to "maximum load capacity" as defined by JATMA, the maximum in "tire load limits at various cold air pressures" as defined by TRA or "load capacity "(Load capacity) as defined by ETRTO. However, in the case of JATMA, in the case of passenger car tires, the prescribed internal pressure is an air pressure of 180 kPa and the prescribed load is 88% of a maximum load capacity.

Modification Example 1

5 FIG. 11 is an explanatory view showing a modification example 1 of the present invention. FIG 1 represents illustrated pneumatic tire.

In the configuration of 2 are three of the main circumferential grooves 21 to 23 arranged. However, the configuration is not limited to this, and three or more of the main circumferential grooves may be used 21 to 24 be arranged (see 5 ).

For example, in Modification Example 1 of FIG 5 four of the main circumferential grooves 21 to 24 arranged to be left-right symmetric in left and right regions delimited by the tire equatorial plane CL. Furthermore, three middle bar sections 32 to 34 and a pair of left and right shoulder land sections 31 and 35 through these main circumferential grooves 21 to 24 assigned. Here are the four main circumferential grooves 21 to 24 and the five bridge sections 31 to 35 from the inside in the vehicle width direction to the outside in the vehicle width direction as a first land portion 31 , first main circumferential groove 21 , second bridge section 32 , second main circumferential groove 22 , third bridge section 33 , third main circumferential groove 23 fourth bridge section 34 , fourth main circumferential groove 24 and fifth bridge section 35 designated.

In addition, the third bridge section 33 on the tire equatorial plane CL and the boundaries of the inner side region and the outer side region are on the second land portion 32 or the fourth bridge section 34 arranged. Thus, the first bridge section belong 31 and a portion of the second land portion 32 to the inside area and a portion of the fourth land portion 34 and the fifth bridge section 35 belong to the outside area. In addition, each of the second web section 32 to the fourth bridge section 34 a plurality of lug grooves 321 . 331 respectively. 341 on and is configured as a series of blocks.

In addition, each of the web sections 31 to 35 a plurality of fins 312 . 322 . 332 . 342 respectively. 352 on. All of the slats 312 and 322 in the first bridge section 31 and the second land portion 32 are arranged in the inner side region, are two-dimensional slats and all of the slats 342 and 352 in the fourth bridge section 34 and the fifth bridge section 35 are arranged in the outer side area, are three-dimensional slats.

It should be noted that the slats 332 in the third bridge section 33 located on the tire equatorial plane CL may be two-dimensional lamellae or three-dimensional lamellae. Alternatively, a combination of two-dimensional slats and three-dimensional slats can be arranged. In a configuration where all in the third bridge section 33 arranged slats 332 two-dimensional lamellae, the steering stability of the tire is improved on snow. In contrast, in a configuration where all slats 332 Three-dimensional fins are the dry steering stability of the tire improved.

In addition, the first bridge section 31 and the second bridge section 32 in the inside area of the upper inside rubber 151_in formed (rubber hardness H1_in and H2_in satisfy 65 ≤ H1_in ≤ 75 and 62 ≤ H2_in ≤ 72) and the fourth land portion 34 and the fifth bridge section 35 in the outside area are made of the upper outer side rubber 151_out formed (rubber hardness H1_out and H2_out satisfy 68 ≤ H1_out ≤ 78 and 65 ≤ H2_out ≤ 75). Therefore, the rigidity of the first land portion becomes 31 and the second land portion 32 set low and the rigidity of the fourth web section 34 and the fifth bridge section 35 is set high.

It should be noted that the third bridge section 33 located on the tire equatorial plane CL from the upper inside rubber 151_in can be formed and also from the upper outer side rubber 151_out can be formed (not shown). In a configuration where the third land portion 33 from the upper inside rubber 151_in is formed, the steering stability of the tire is improved on snow. In contrast, in a configuration where the third land portion 33 from the upper outer side rubber 151_out is formed, improves the dry steering stability of the tire.

At the pneumatic tire 1A from 5 points each of the middle bridge sections 32 to 34 the openly formed lug grooves 321 until respectively 341 and is therefore each formed as a series of blocks. In addition, the left and right shoulder web section 31 and 35 each semi-closed lug grooves 311 and 351 on and they are therefore designed as ribs. However, the configuration is not limited thereto, and each of the land portions may have lug grooves having an open structure or a half-closed structure or lug grooves having a closed structure (not shown). Furthermore, each of the web portions may be formed as a series of blocks or as a rib (not shown). In addition, each of the web portions may have inclined grooves (not shown).

Also, in the pneumatic tire 1A from 5 the slats 312 to 352 the bridge sections 31 to 35 each closed lamellae. However, the configuration is not limited to this, and each of the fins 312 to 352 may be an open sipe or a semi-closed sipe (not shown).

Modification Example 2

6 FIG. 11 is an explanatory view showing a modification example 2 of the embodiment of FIG 1 represents illustrated pneumatic tire. This drawing shows a winter tire for use on passenger cars having an asymmetric tread pattern.

In the configuration of 2 points the pneumatic tire 1A a left-right symmetric tread pattern wherein the fin configuration and rubber hardness thereof are left-right-asymmetric. However, the configuration is not limited to this, and the pneumatic tire 1A can a left have right-asymmetric tread pattern (see 6 ).

For example, in Modification Example 2 of FIG 6 the pneumatic tire 1A three of the circumferential main circumferential grooves 21 to 23 and four of the bridge sections 31 to 34 coming from the main circumferential grooves 21 to 23 divided and formed in the tread portion on. In addition, a ground contact width of the first land portion 31 in the inner side area larger than a ground contact width of the fourth land portion 34 in the outside area. In addition, the first web section 31 a plurality of inclined grooves 313 that are inclined with respect to the tire circumferential direction, a plurality of first lug grooves 314_a and 314_b extending in the tire width direction from an outer side of the ground contact patch of the tire, so that they with the inclined grooves 313 are connected, and a plurality of second lug grooves 315_a to 315_c that run in the tire width direction so that they are the inclined grooves 313 and the first circumferential main groove 21 connect, up. There are also three of the first lug grooves 314 with one of the inclined grooves 313 connected. It should be noted that a number of the first lug grooves 314 is preferably in a range of not less than 3 and not more than 6.

In addition, in the modification example 2 of 6 an arrangement pitch in the tire circumferential direction of the second lug grooves 315_a to 315_c narrower than an arrangement pitch in the tire circumferential direction of the first lug grooves 314_a and 314_b , As a result, the water drainage properties and the snow traction properties of the first land portion become 31 elevated. In addition, there is an inclination angle θ of the inclined grooves 313 with respect to the tire circumferential direction within a range of 10 [degrees] ≦ θ ≦ 40 [degrees]. As a result, the inclination angle θ of the inclined grooves becomes 313 set appropriately. In addition, each have all or a portion of the second lug grooves 315_b and 315_c from the plurality of second lug grooves 315_a to 315_c raised bottom portions (not shown) in which the groove bottoms are increased. As a result, the raised floor sections enhance the rigidity of the land section 31 ,

In addition, a groove width W3 (not shown) of the second lug grooves 315_a to 315_c set in a range of 2 mm ≦ W3 ≦ 6 mm. As a result, the groove width W3 of the second lug grooves becomes 315_a to 315_c set appropriately. Furthermore, the second web section 32 and the third bridge section 33 each a plurality of lug grooves 321 and 331 on top of the bridge sections 32 respectively. 33 penetrate in the tire width direction. In addition, all or a portion of the lug grooves each of the plurality of lug grooves 321 and 331 raised bottom portions (not shown) in which the groove bottoms are increased. As a consequence, the raised floor sections increase the rigidity of the land sections 32 and 33 ,

In addition, from the tire equatorial plane CL, a distance DE to a ground contact edge T of the tire, a distance D1 to (a groove center line) of the first circumferential main groove 21 that the first bridge section 31 divides, and a distance D3 to the third circumferential main groove 23 that the fourth bridge section 34 divides such relationships that 0.10 ≦ D1 / DE ≦ 0.30 (preferably 0.15 ≦ D1 / DE ≦ 0.25) and 0.55 ≦ D3 / DE ≦ 0.75. Here, it is assumed that the first circumferential main groove 21 and the third circumferential main groove 23 are arranged so that the tire equatorial plane CL lies between them. As a result, the relationship between the ground contact width of the left and right first land portions becomes 31 and fourth bridge section 34 set appropriately. It should be noted that in the modification example 2 of 6 a distance D2 from the tire equatorial plane CL to the second circumferential main groove 22 so is that D2 = D1.

In addition, the first web section 31 a narrow and shallow circumferential groove 25 on, between the inclined grooves 313 and the ground contact edge T of the tire is disposed and extends in the tire circumferential direction. A groove width W2 (not shown) and a groove depth Hd3 (not shown) of the narrow and shallow circumferential groove 25 are set to be in ranges of 2 mm ≤ W2 ≤ 4 mm and 2 mm ≤ Hd3 ≤ 4 mm. As a result, the snow traction properties become due to the edge components of the narrow and shallow circumferential groove 25 improved. It should be noted that in the modification example 2 of 6 a distance D4 from the tire equatorial plane CL to the narrow and shallow circumferential groove 25 such that 0.50 ≤ D4 / DE ≤ 0.90.

In the modification example 2 of 6 As described above, the first land portion 31 in the inside area a wide structure and the first bridge section 31 has the plurality of inclined grooves 313 , the majority of first lug grooves 314_a and 314_b and the plurality of second lug grooves 315_a to 315_c on. Therefore, the rigidity of this wide first land portion becomes 31 reduces and the Wasserabflusseigenschaften the first web section 31 be ensured. Because three or more of the first lug grooves 314_a and 314_b with one of the inclined grooves 313 In addition, the water drainage properties and the snow traction properties of the first land portion become 31 improved. As a result, the dry performance, wet performance and snow performance of the tire can be achieved.

In addition, in the modification example 2 of 6 the bridge sections 31 to 34 each of the plurality of slats 312 to 342 on. Each block of the first bridge section 31 that of the inclined grooves 313 , the first lug groove 314_a and 314_b and the second lug grooves 315_a to 315_c is divided, has a plurality of fins 312 on. Furthermore, not less than 90% of the fins exist 312 in the first bridge section 31 are arranged, consisting of two-dimensional slats and not less than 90% of the slats 332 and 342 in the third bridge section 33 and the fourth bridge section 34 are arranged, consist of three-dimensional slats. In addition, the rubber hardnesses are H1_in and H2_in of the upper rubber 151_in of the first bridge section 31 and the rubber hardnesses H1_out and H2_out of the upper rubber 151_out of the third bridge section 33 and the fourth bridge section 34 such relationships that H1_in <H1_out and H2_in <H2_out.

It should be noted that the slats 322 in the second bridge section 32 located on the tire equatorial plane CL may be two-dimensional lamellae or three-dimensional lamellae. Alternatively, a combination of two-dimensional slats and three-dimensional slats can be arranged. In a configuration where all in the second bridge section 32 arranged slats 322 two-dimensional lamellae, the steering stability of the tire is improved on snow. In contrast, in a configuration where all slats 322 Three-dimensional fins are the dry steering stability of the tire improved.

In addition, the first bridge section 31 in the inside area of the upper inside rubber 151_in formed (rubber hardness H1_in and H2_in satisfy 65 ≤ H1_in ≤ 75 and 62 ≤ H2_in ≤ 72) and the third land portion 33 and the fourth bridge section 34 in the outside area are made of the upper outer side rubber 151_out formed (rubber hardness H1_out and H2_out satisfy 68 ≤ H1_out ≤ 78 and 65 ≤ H2_out ≤ 75). Therefore, the rigidity of the first land portion becomes 31 set low and the rigidity of the third land section 33 and the fourth bridge section 34 is set high.

The second bridge section 32 located on the tire equatorial plane CL can be made of the upper inside rubber 151_in can be formed and also from the upper outer side rubber 151_out are formed (not shown). In a configuration where the second land portion 32 from the upper inside rubber 151_in is formed, the steering stability of the tire is improved on snow. In contrast, in a configuration where the second land portion 32 from the upper outer side rubber 151_out is formed, improves the dry steering stability of the tire.

In addition, in the modification example 2 of 6 the pneumatic tire 1A a display indicative of a mounting direction on a vehicle, wherein the first land portion 31 having a wide ground contact width is disposed on the inside in the vehicle width direction. In typical high-performance vehicles, a configuration in which a large negative camber angle is set is used, and therefore, the ground contact area of the tire in the vehicle width direction inner side area increases. Therefore, the snow traction properties are effectively improved because of the pneumatic tire 1A mounted on the vehicle so that the first bridge section 31 on the inside in the vehicle width direction.

It is to be noted that the ground contact edge T of the tire and the ground contact width of the tire at a contact surface between a tire and a flat plate in a configuration in which the tire is mounted on a standard rim fill to a prescribed internal pressure with respect to the flat Plate is placed vertically in a static state and loaded with a load corresponding to a prescribed load, provided or measured.

Effects A

As described above, the pneumatic tire 1A the plurality of main circumferential grooves 21 to 23 extending in the tire circumferential direction and the plurality of land portions 31 to 34 coming from the main circumferential grooves 21 to 23 divided and formed in the tread portion on (see 2 ). In addition, each of the plurality of web portions 31 to 34 the majority of lamellae 312 until respectively 342 on. Furthermore, not less than 90% of the fins exist 312 and 322 , which are arranged in the inside area, of two-dimensional slats and not less than 90% of the slats 332 and 342 , which are arranged in the outer side area, consist of three-dimensional slats. In addition, the tread portion has the upper rubber 151 and the lower rubber 152 on (see 1 ). The rubber hardness H1_in at -10 ° C and the rubber hardness H2_in at 20 ° C of the upper rubber 151_in in the inside area and the rubber hardness H1_out at -10 ° C and the rubber hardness H2_out at 20 ° C of the upper rubber 151_out in the outer side area, such relationships are H1_in <H1_out and H2_in <H2_out.

In the configuration described above, the two-dimensional fins are 312 and 322 arranged in the inner side area and the three-dimensional slats 332 and 342 are arranged in the outer side area. Therefore, the rigidity in the inside area is set low and the rigidity in the outside area is set high (see 2 ). In addition, the rubber hardnesses H1_in and H2_in in the inner side region and the rubber hardnesses H1_out and H2_out in the outer side region have such relationships that H1_in <H1_out and H2_in <H2_out. Therefore, the rigidity in the inside area is set low and the rigidity in the outside area is set high. Thus, there is a synergistic decrease in inside-side stiffness and a synergistic increase in outside-side stiffness. As a result, when wearing the pneumatic tire 1A is mounted to a vehicle such that the inside area is on the inside in the vehicle width direction, the inside area greatly contributes to improving the steering stability on snow, and the outside area greatly contributes to improving dry steering stability. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are largely achieved.

In addition, fulfill in the pneumatic tire 1A the rubber hardnesses H1_in and H2_in in the inside area and the rubber hardnesses H1_out and H2_out in the outside area have the conditions: 65 ≦ H1_in ≦ 75, 62 ≦ H2_in ≦ 72, 68 ≦ H1_out ≦ 78 and 65 ≦ H2_out ≦ 75, and 3 ≦ H1_out-H1_in ≦ 10 and 3 ≦ H2_out - H2_in ≦ 10. In the configuration described above, the ranges of the rubber hardnesses H1_in and H2_in in the inside area and the rubber hardnesses H1_out and H2_out in the outside area and the rubber hardness difference between the inside area and the outside area are appropriately set. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, in the pneumatic tire 1A the sipe density D_in of the inside area and the sipe density D_out of the outside area have such a relationship that 1.2 ≦ D_in / D_out ≦ 2.0. With such a configuration, the ratio D_in / D_out of the sipe density D_in of the inner side region to the sipe density D_out of the outer side region is appropriately set. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, in the pneumatic tire 1A the groove area ratio S_in of the inner side area and the groove area ratio S_out of the outer side area in the ground contact patch of the tire are such that 1.2 ≦ S_in / S_out ≦ 2.0, and the total groove area ratio S_t in the ground contact patch of the tire is within the range of 0, 25 ≤ S_t ≤ 0.38. In the above-described configuration, the ratio S_in / S_out of the groove area ratio S_in in the inside area to the groove area ratio S_out in the outside area, and the total groove area ratio S_t are set appropriately. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, the pneumatic tire points 1A three of the main circumferential grooves 21 to 23 and four of the bridge sections 31 to 34 in the tread section (see 6 ). In addition, the ground contact width of the first land portion 31 at the bottom contact edge T in the inner side region greater than the ground contact width of the fourth web portion 34 at the ground contact edge T in the outer side area. In addition, the first web section 31 the majority of inclined grooves 313 that are inclined with respect to the tire circumferential direction, the plurality of first lug grooves 314_a and 314_b extending in the tire width direction from the outside of the ground contact patch of the tire, so that they with the inclined grooves 313 are connected, and the plurality of second lug grooves 315_a to 315_c that run in the tire width direction so that they are the inclined grooves 313 and the main circumferential groove 21 connect, up. In addition, three or more of the first lug grooves 314_a and 314_b with one of the inclined grooves 313 connected.

In the configuration described above, the first land portion 31 in the inside area a wider structure and the first bridge section 31 has the plurality of inclined grooves 313 , the majority of first lug grooves 314_a and 314_b and the plurality of second lug grooves 315_a to 315_c on. Therefore, the rigidity of this wide first land portion becomes 31 reduces and the Wasserabflusseigenschaften the first web section 31 be ensured. Because three or more of the first lug grooves 314_a and 314_b with one of the inclined grooves 313 In addition, the water drainage properties and the snow traction properties of the first land portion become 31 improved. Such a configuration is advantageous because dry performance, wet performance and snow performance of the tire can be achieved.

In addition, the pneumatic tire points 1A the indicator on which the mounting direction (see 2 ) on a vehicle, wherein the inside area is on the inside in the vehicle width direction. In the above-described configuration, the inner side region with the low rigidity is disposed on the vehicle width direction inner side, and the outer rigidity high outside region is on the outer side in FIG Vehicle width direction arranged. Such a configuration is advantageous because the inner side area greatly contributes to steering stability on snow, the outer side area greatly contributes to dry steering stability, and both dry steering stability and steering stability of the tire on snow are largely achieved.

Example A

8th FIG. 14 is a table showing the performance test results of pneumatic tires according to Embodiment 1 of the present invention. FIG.

• (1) Bei den Bewertungen der Trockenlenkstabilität wurde das Testfahrzeug, an dem die Luftreifen montiert waren mit einer Geschwindigkeit von 60 km/h bis 240 km/h auf einer flachen Teststrecke gefahren. Dann führte der Testfahrer eine sensorische Bewertung hinsichtlich des Lenkens bei Fahrspurwechsel und Kurvenfahren und der Stabilität beim Vorwärtsfahren durch. Die Ergebnisse der Bewertungen wurden indiziert und der Indexwert des Luftreifens des Vergleichsbeispiels 1 wurde als Standardpunktwert (100) verwendet. Höhere Punktebewertungen waren bevorzugt.
• (2) Bei den Bewertungen der Lenkstabilität auf Schnee wurde das Testfahrzeug, an dem die Luftreifen montiert waren, mit einer Geschwindigkeit von 40 km/h auf einem Handlingparcours in einer Schneeteststreckeneinrichtung gefahren und der Testfahrer führte eine sensorische Bewertung durch. Die Ergebnisse der Bewertungen wurden indiziert und der Indexwert des Luftreifens des Vergleichsbeispiels 1 wurde als Standardpunktwert (100) verwendet. Höhere Punktebewertungen waren bevorzugt.

In the performance tests, a plurality of different pneumatic tires were evaluated for (1) dry steering stability and (2) steering stability on snow (see 8th ). In these performance tests, pneumatic tires with a tire size of 235 / 45R19 were mounted on rims with a rim size of 19 × 8J, filled to an air pressure of 250 kPa and loaded with 85% of a "load capacity" according to ETRTO. A saloon with four-wheel drive and a displacement of 3.0 l was used as a test vehicle.

• (1) In dry steering stability evaluations, the test vehicle on which the pneumatic tires were mounted was run at a speed of 60 km / h to 240 km / h on a flat test track. Then, the test driver made a sensory evaluation regarding steering in lane change and cornering, and stability in forward driving. The results of the evaluations were indexed and the index value of the pneumatic tire of Comparative Example 1 was used as a standard score (100). Higher scores were preferred.
• (2) In the steering stability evaluations on snow, the test vehicle on which the pneumatic tires were mounted was driven at a speed of 40 km / h on a handling course in a snow test track device, and the test driver conducted a sensory evaluation. The results of the evaluations were indexed and the index value of the pneumatic tire of Comparative Example 1 was used as a standard score (100). Higher scores were preferred.

The pneumatic tire 1A of Embodiment 1 had the structure of 1 and the tread pattern of 2 and had three main circumferential grooves 21 to 23 and four bridge sections 31 to 34 in the tread section. In addition, all of the lamellae existed 312 and 322 in the first bridge section 31 and the second land portion 32 in the inside area of two-dimensional slats and all of the slats 332 and 342 in the third bridge section 33 and the fourth bridge section 34 in the outer side area consisted of three-dimensional lamellae. Furthermore, the rubber hardnesses were H1_in and H2_in of the upper rubber 151_in in the inner side area smaller than the rubber hardnesses H1_out and H2_out of the upper rubber 151_out in the outer side area (H1_in <H1_out and H2_in <H2_out). In addition, the sipe density D_in of the inner side portion was larger than the sipe density D_out of the outer side portion (1.00 <D_in / D_out). In addition, the groove area ratio S_in in the inner side area and the groove area ratio S_out in the outer side area of the ground contact patch of the tire were set by the groove area or the arrangement pitch of the lug grooves of the land portions 31 to 34 was set. The pneumatic tires 1A Embodiments 2 to 9 are modification examples of the pneumatic tire 1A of embodiment 1.

Besides, had the pneumatic tire 1A of embodiment 10 the in 5 shown structure and had four main circumferential grooves 21 to 24 and five bridge sections 31 to 35 in the tread section. The pneumatic tire 1A of Embodiment 11, the tread pattern of FIG 6 on. Furthermore, the boundary was between the upper rubber 151_in the inner side region and the upper rubber 151_out of the outside area on the first circumferential main groove 21 , In addition, all of the lamellae existed 312 of the first bridge section 31 from two-dimensional slats, and all of the slats 322 to 342 of the second land section 32 to the fourth bridge section 34 consisted of the three-dimensional lamellae.

The pneumatic tire of the prior art example 1 had three main circumferential grooves and four land portions in the tread portion. In addition, all of the fins in each of the land portions were two-dimensional fins. Further, the rubber hardnesses H1_in and H2_in of the upper rubber of the land portions in the inner side region were smaller than the rubber hardnesses H1_out and H2_out of the upper rubber of the land portions in the outer side region. In addition, the sipe density D_in of the inner side portion was larger than the sipe density D_out of the outer side portion.

In contrast to the pneumatic tire of the prior art example 1, in the pneumatic tire of the prior art example 2, the rubber hardnesses H1_in and H2_in of the upper rubber of the land portions in the inner side area were larger than the rubber hardnesses H1_out and H2_out of the upper rubber of the land portions in the outer side area. In addition, the sipe density D_in of the inner side portion was smaller than the sipe density D_out of the outer side portion.

The pneumatic tires of Comparative Examples 1 to 3 are different from the pneumatic tire 1A of the embodiment 1 with respect to the lamella shape in the Web portions in the inner side region and the web portions in the outer side region and the hardness difference of the upper rubber.

As the test results show, the pneumatic tires are 1A of the embodiments 1 to 11 compared to the pneumatic tire of the example of the prior art 1 improves the dry steering stability and the steering stability on snow of the tires (see 8th ). In addition, in a comparison of Embodiments 1 to 3, it is apparent that both the dry steering stability and the steering stability of the tire on snow are achieved because the rubber hardness difference between the inside and outside regions is appropriately set. Moreover, comparing Embodiments 1, 4 and 5, it becomes clear that both the dry steering stability and the steering stability of the tire on snow are achieved because the ratio D_in / D_out of the sipe density D_in of the inner side region to the sipe density D_out of the outer side region is appropriately set. In addition, comparing Embodiments 1 and 6 to 9, it becomes clear that both the dry steering stability and the steering stability of the tire are achieved on snow, because the ratio S_in / S_out of the groove area ratio S_in in the inside area to the outside area ridge area ratio S_out and the total groove area ratio S_t are suitable be set.

A pneumatic tire of Embodiment 2

At the pneumatic tire 1A of Embodiment 1 as described above, not less than 90% of the fins exist 312 and 322 , which are arranged in the inside area, of two-dimensional slats and not less than 90% of the slats 332 and 342 , which are arranged in the outer side area, consist of three-dimensional lamellae (see 1 and 2 ). In addition, the rubber hardness H1_in at -10 ° C and the rubber hardness H2_in at 20 ° C of the upper rubber 151_in in the inside area and the rubber hardness H1_out at -10 ° C and the rubber hardness H2_out at 20 ° C of the upper rubber 151_out in the outer-side area, such relationships that H1_in <H1_out and H2_in <H2_out. Further, the tire is mounted on a vehicle such that the inside area is on the inside in the vehicle width direction.

Unlike the pneumatic tire 1A of Embodiment 1 are in a pneumatic tire 1B of Embodiment 2, the lamination configurations and the rubber hardness configurations of the inside and outside regions are reversed. That is, not less than 90% of the slats 312 * and 322 * , which are arranged in the inner side area, consist of three-dimensional slats and not less than 90% of the slats 332 * and 342 * , which are arranged in the outer side area, consist of two-dimensional slats (see 1 and 2 ). A rubber hardness H1_in * at -10 ° C and a rubber hardness H2_in * at 20 ° C of the upper rubber 151_in * in the inside area and a rubber hardness H1_out * at -10 ° C and a rubber hardness H2_out * at 20 ° C of the upper rubber 151_out * in the outside area, such relationships are H1_in *> H1_out * and H2_in *> H2_out *. Further, the tire is mounted on a vehicle such that the inside area is on the inside in the vehicle width direction. As a consequence, the pneumatic tire 1B of Embodiment 2 other properties than the pneumatic tire 1A of embodiment 1.

A description of the pneumatic tire 1B of Embodiment 2 is given below.

It should be noted that components of the pneumatic tire 1B of embodiment 2, with those of the pneumatic tire 1A of Embodiment 1 are assigned the same reference numerals and descriptions thereof have been omitted. In addition, components that are different are marked and marked with an asterisk (*).

Slat configuration and rubber hardness

At the pneumatic tire 1B points each of the web sections 31 to 34 a plurality of fins 312 * until respectively 342 * on (see 2 ). Furthermore, not less than 90% of the fins exist 312 * and 322 * , which are arranged in the inside area, of three-dimensional slats and not less than 90% of the slats 332 * and 342 * , which are arranged in the outer side area, consist of two-dimensional slats.

In addition, in Embodiment 2, each of the land portions 31 to 34 the majority of lamellae 312 * until respectively 342 * on. In addition, the slats 312 * to 342 * a straight shape extending in the tire width direction, and are respectively arranged parallel to each other in the tire circumferential direction and at a predetermined pitch. Furthermore, the slats 312 * to 342 * a closed structure, each within the web sections 31 to 34 ending. In addition, the slats 312 * of the first bridge section 31 and the slats 322 * of the second land section 32 three-dimensional slats and the slats 332 * of the third bridge section 33 and the slats 342 * of the fourth bridge section 34 are each two-dimensional slats. Thus, due to a stiffness difference between the three-dimensional slats 312 * and 322 * and the two-dimensional slats 332 * and 342 * the rigidity of the first web section 31 and the second land portion 32 set on the inside in the vehicle width direction, set high and the rigidity of the third land portion 33 and the fourth bridge section 34 set low on the outside in the vehicle width direction.

In addition, in the pneumatic tire 1B the tread portion is an upper rubber 151 and a lower rubber 152 on (see 1 ). A rubber hardness H1_in * at -10 ° C and a rubber hardness H2_in * at 20 ° C of the upper rubber 151_in * in the inside area and a rubber hardness H1_out * at -10 ° C and a rubber hardness H2_out * at 20 ° C of the upper rubber 151_out * in the outer side area, such relationships are H1_in *> H1_out * and H2_in *> H2_out * (see 1 ).

For example, in Embodiment 2, the upper rubber is 151 from an upper inside rubber 151_in * and an upper outside rubber 151_out * educated. The upper inside rubber 151_in * is disposed in an inner side region and the upper outer side rubber 151_out * is arranged in an outside area. There is a boundary between the upper inside rubber 151_in * and the upper outside rubber 151_out * under a groove bottom of the second circumferential main groove 22 which is disposed on the tire equatorial plane CL. The rubber hardnesses H1_in * and H2_in * of the upper inside rubber 151_in * and the rubber hardnesses H1_out * and H2_out * of the upper outside rubber 151_out * have such relationships that H1_in *> H1_out * and H2_in *> H2_out *. Thus, due to a rubber hardness difference, the upper rubbers become 151_in * and 151_out * the rigidity of the first web section 31 and the second land portion 32 , which are arranged in the inner side area, set high and the rigidity of the third land portion 33 and the fourth bridge section 34 which are located in the outer side area is set low.

At the pneumatic tire 1B are the three-dimensional slats 312 * and 322 * arranged in the inner side area and the two-dimensional slats 332 * and 342 * are arranged in the outer side area. Therefore, the rigidity in the inside area is set high and the rigidity in the outside area is set low (see 2 ). In addition, the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * in the outside area have such relationships that H1_in *> H1_out * and H2_in *> H2_out *. Therefore, the rigidity in the inside area is set high, and the rigidity in the outside area is set low. Thus, there is a synergistic increase in inside-side stiffness and a synergistic decrease in outside-side stiffness. As a result, when wearing the pneumatic tire 1B is mounted on a vehicle such that the inner side portion is located on an inner side in the vehicle width direction, the inner side portion greatly contributes to improving the dry steering stability, and the outer side portion greatly contributes to improving the steering stability on snow. As a result, both dry steering stability and steering stability of the tire on snow are achieved to a high degree.

In addition, in the configuration described above, the rigidity in the inner side area is high, and therefore, when the pneumatic tire 1B is mounted on a vehicle with a large camber angle, that the inner side portion is located on the inside in the vehicle width direction, the rigidity of the tread portion to a large extent maintained. As a result, the durability performance of the tire at high speed is improved. In addition, in the above-described mounting state, the ground contact length of the tire on the inside in the vehicle width direction increases. As described above, the rigidity in the inner side area is high, resulting in a further improvement of the dry performance of the tire.

With regard to this point, the pneumatic tire points 1B Preferably, a display defining a mounting orientation on a vehicle, wherein a camber angle δ (not shown) in a range -4 ° ≤ δ ≤ 0 °. By mounting the tire 1B In a vehicle having the camber angle δ described above, functions of the inner side portion having the high rigidity suitably show, and the durability performance of the tire at high speed is effectively improved. It should be noted that the above-described display can be made, for example, by marks or recesses and protrusions provided in the sidewall portion of the tire or in a catalog attached to the tire.

In the configuration described above, the rubber hardnesses H1_in * and H2_in * in the inner side region and the rubber hardnesses H1_out * and H2_out * in the outer side region preferably satisfy the conditions: 68 ≦ H1_in * ≦ 78, 65 ≦ H2_in * ≦ 75, 65 ≦ H1_out * ≦ 75, and 62 ≦ H2_out * ≦ 72, and 3 ≦ H1_in * - H1_out * ≦ 10 and 3 ≦ H2_in * - H2_out * ≦ 10. As a result, the relationship between the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * set in the outside area suitable.

In addition, in the above-described configuration, a sipe density D_in * of the inner side region and a sipe density D_out * of the outer side region preferably have a relationship such that 1.2 ≦ D_out * / D_in * ≦ 2.0. That is, the sipe density D_in * of the inner side portion is preferably smaller than the sipe density D_out * of the outer side portion. As a result, the relationship between the sipe density D_in * of the inner side portion and the sipe density D_out * of the outer side portion is appropriately set.

As described above, in the pneumatic tire 1B due to the arrangement of the three-dimensional lamellae 312 * and 322 * and the two-dimensional lamellae 332 * and 342 * and the rubber hardness difference between the upper rubber 151_in * in the inside area and the upper rubber 151_out * in the outer side, the rigidity of the web sections 31 and 32 set the inner side area high and the rigidity of the web sections 33 and 34 the outside area is set low. Thus, by providing the difference between the disk densities D_in * and D_out * as described above, the rigidity of the land portions 31 and 32 the inner side area are set even higher and the rigidity of the web sections 33 and 34 the outside area can be set even lower.

In addition, in the above-described configuration, a groove area ratio S_in * of the inner side area and a groove area ratio S_out * of the outer side area in a ground contact patch of the tire preferably have a relationship such that 1.2 ≦ S_out * / S_in * ≦ 2.0, and a total groove area ratio S_t in the ground contact patch of the tire is preferably within a range of 0.25 ≦ S_t ≦ 0.38. As a result, a ratio S_out * / S_in * of the groove area ratio S_out * of the outside area to the groove area ratio S_in * of the inside area, and the total groove area ratio S_t are set appropriately.

In addition, in the pneumatic tire 1B a groove width W1 * of the lug grooves 311 the inner side portion (not shown) and a groove width W2 * of the lug grooves 341 of the outer side portion (not shown) preferably has such a relationship that 0.5 mm ≦ W2 * - W1 * ≦ 2.0 mm. In the above-described configuration, the lug grooves are 311 of the inner side portion narrow, and therefore, the dry steering stability and the durability performance of the tire are improved at high speed. In addition, the lug grooves 341 the outside area wide and therefore the performance of the tire on snow is improved.

In addition, in the pneumatic tire 1B a groove depth Hd1 * (not shown) of the lug grooves 311 of the inner side portion and a groove depth Hd2 * (not shown) of the lug grooves 341 of the outer side portion preferably has a relationship such that 1.0 mm ≦ Hd2 * - Hd1 * ≦ 3.0 mm. In the configuration described above, the groove depth is Hd1 * of the lug grooves 311 of the inner side portion is shallow, and therefore, in particular, the durability performance of the tire at high speed is improved. In addition, the lug grooves 341 the outside area deep and therefore the performance of the tire on snow is improved.

Modification Example 3

In the configuration of 2 are three of the main circumferential grooves 21 to 23 arranged. However, the configuration is not limited to this, and three or more of the main circumferential grooves may be used 21 to 24 be arranged (see 5 ).

For example, in the pneumatic tire 1B from 5 each of the bridge sections 31 to 35 a plurality of fins 312 * . 322 * . 332 * . 342 * respectively. 352 * on. All of the slats 312 * and 322 * in the first bridge section 31 and the second land portion 32 of the inner side portion are three-dimensional slats and all of the slats 342 * and 352 * in the fourth bridge section 34 and the fifth bridge section 35 of the outside area are two-dimensional louvers.

It should be noted that the slats 332 * in the third bridge section 33 located on the tire equatorial plane CL may be two-dimensional lamellae or three-dimensional lamellae. Alternatively, a combination of two-dimensional slats and three-dimensional slats can be arranged. In a configuration where all in the third bridge section 33 arranged slats 332 * two-dimensional lamellae, the steering stability of the tire is improved on snow. In contrast, in a configuration where all slats 332 * Three-dimensional fins are the dry steering stability of the tire improved.

In addition, the first bridge section 31 and the second bridge section 32 of the inner side portion of the upper inner side rubber 151_in * formed (rubber hardnesses H1_in * and H2_in * satisfy 68 ≤ H1_in * ≤ 78 and 65 ≤ H2_in * ≤ 75) and the fourth land portion 34 and the fifth bridge section 35 of the outside area are made of the upper outside rubber 151_out * formed (rubber hardness H1_out * and H2_out * meet 65 ≤ H1_out * ≤ 75 and 62 ≤ H2_out * ≤ 72). Therefore, the rigidity of the first land portion becomes 31 and the second land portion 32 set high and the rigidity of the fourth web section 34 and the fifth bridge section 35 is set low.

It should be noted that the third bridge section 33 located on the tire equatorial plane CL from the upper inside rubber 151_in can be formed and also from the upper outer side rubber 151_out * can be formed (not shown). In a configuration where the third land portion 33 from the upper inside rubber 151_in * is formed, the dry steering stability of the tire is improved. In contrast, in a configuration where the third land portion 33 from the upper outer side rubber 151_out * which improves steering stability of the tire on snow.

Also, in the pneumatic tire 1B from 5 the slats 312 * to 352 * the bridge sections 31 to 35 each closed lamellae. However, the configuration is not limited to this and each of the fins 312 * to 352 * may be an open sipe or a semi-closed sipe (not shown).

Modification Example 4

In the configuration of 2 points the pneumatic tire 1B a left-right symmetric tread pattern wherein the fin configuration and rubber hardness thereof are left-right-asymmetric. However, the configuration is not limited to this and the pneumatic tire 1B may have a left-right-asymmetric tread pattern (see 6 ).

For example, in the pneumatic tire 1B from 6 each of the bridge sections 31 to 34 a plurality of fins 312 * until respectively 342 * on. Each block of the first bridge section 31 that of the inclined grooves 313 , the first lug groove 314_a and 314_b and the second lug grooves 315_a to 315_c is divided, has a plurality of fins 312 * on. Furthermore, not less than 90% of the fins exist 312 * in the first bridge section 31 are arranged from three-dimensional slats and not less than 90% of the slats 332 * and 342 * in the third bridge section 33 and the fourth bridge section 34 are arranged, consist of two-dimensional slats. In addition, the rubber hardnesses H1_in * and H2_in * of the upper rubber 151_in * of the first bridge section 31 and the rubber hardnesses H1_out * and H2_out * of the upper rubber 151_out * of the third bridge section 33 and the fourth bridge section 34 such relationships on that H1_in *> H1_out * and H2_in *> H2_out *.

It should be noted that the slats 322 * in the second bridge section 32 located on the tire equatorial plane CL may be two-dimensional lamellae or three-dimensional lamellae. Alternatively, a combination of two-dimensional slats and three-dimensional slats can be arranged. In a configuration where all in the second bridge section 32 arranged slats 322 * two-dimensional lamellae, the steering stability of the tire is improved on snow. In contrast, in a configuration where all slats 322 * Three-dimensional fins are the dry steering stability of the tire improved.

In addition, the first bridge section 31 of the inner side portion of the upper inner side rubber 151_in * formed (rubber hardnesses H1_in * and H2_in * satisfy 68 ≤ H1_in * ≤ 78 and 65 ≤ H2_in * ≤ 75) and the third land portion 33 and the fourth bridge section 34 of the outside area are made of the upper outside rubber 151_out * formed (rubber hardness H1_out * and H2_out * meet 65 ≤ H1_out * ≤ 75 and 62 ≤ H2_out * ≤ 72). Therefore, the rigidity of the first land portion becomes 31 set high and the rigidity of the third land section 33 and the fourth bridge section 34 is set low.

The second bridge section 32 located on the tire equatorial plane CL can be made of the upper inside rubber 151_in * can be formed and also from the upper outer side rubber 151_out * are formed (not shown). In a configuration where the third land portion 33 from the upper inside rubber 151_in * is formed, the dry steering stability of the tire is improved. In contrast, in a configuration where the third land portion 33 from the upper outer side rubber 151_out * which improves steering stability of the tire on snow.

In addition, in the modification example 4 of 6 the pneumatic tire 1B a display indicative of a mounting direction on a vehicle, wherein the first land portion 31 having a wide ground contact width is disposed on the inside in the vehicle width direction. In typical high-performance vehicles, a configuration in which a large negative camber angle is set is used, and therefore, the ground contact area of the tire in the vehicle width direction inside section increases. Therefore, the snow traction properties are effectively improved because of the pneumatic tire 1B mounted on the vehicle so that the first bridge section 31 on the inside in the vehicle width direction. In addition, as described above, the rigidity of the first land portion 31 high, and therefore, by mounting the tire such that the first land portion 31 on the inside in vehicle width direction is maintained, the rigidity of the tread portion at a high level. As a result, the durability performance of the tire at high speed is improved.

Modification Example 5

7 FIG. 11 is an explanatory view showing a modification example 5 of the embodiment of FIG 1 represents illustrated pneumatic tire. This drawing shows a winter tire for use on passenger cars having a directional tread pattern.

As in 7 shown, the pneumatic tire 1B have a directional tread pattern. It should be noted that the pneumatic tire described above 1B has an indication of the direction of rotation on the basis of the forward direction of the vehicle, because such tires generally have an indication of the mounting direction of the tire on a vehicle.

For example, in the modification example 5 of FIG 7 the pneumatic tire 1B two of the main circumferential grooves 21 and 22 extending in the tire circumferential direction and three of the land portions 31 to 33 coming from the main circumferential grooves 21 and 22 be divided and trained on. In particular, the two main circumferential grooves become 21 and 22 arranged to be left-right symmetric in left and right regions delimited by the tire equatorial plane CL. Furthermore, a middle web section 32 and a pair of left and right shoulder land sections 31 and 33 from this main circumferential groove 21 and 22 assigned. In addition, there is a boundary of the inside area and a boundary of the outside area in the middle land portion 32 , Therefore, the left and right main circumferential grooves are 21 and 22 arranged in the inner side region or the outer side region.

Here are the left and right main circumferential grooves 21 and 22 which are located entirely outside in the tire width direction, referred to as "outermost circumferential grooves". A region on an inner side in the tire width direction of the tread portion defined by groove center lines of the left and right outermost circumferential main grooves is referred to as "center region" and the left and right regions on outer sides in the tire width direction are referred to as "shoulder regions".

In addition, the tire equatorial plane CL is located at a central portion of the central land portion 32 , Further, a distance D5 from the tire equatorial plane CL to the groove centerline of a first circumferential main groove 21 (or a second circumferential main groove 22 ) and a distance DE from the tire equatorial plane CL to the left and right ground contact edges T of the tire have such a relationship that 0.40 ≦ D5 / DE ≦ 0.60.

In addition, the middle bridge section has 32 a rib-like structure and has a plurality of inclined main grooves 323 and a plurality of smaller inclined grooves 324 on.

The inclined main grooves 323 are inclined with respect to the tire circumferential direction in such a shape as to be aligned in a single direction in the tire circumferential direction and away from the tire equatorial plane CL. In addition, the majority of inclined main grooves 323 arranged in the tire circumferential direction at a predetermined pitch and is alternately arranged in the tire circumferential direction on both sides of the tire equatorial plane CL. Further, a first end (trailing end with respect to the tire rotation direction) is each of the inclined main grooves 323 with the left or right main circumferential groove 21 or 22 connected. In addition, there is an angle δ1, the inclined main grooves 323 with the main circumferential groove 21 at the first end of the inclined main grooves 323 within a range of 56 [degrees] ≦ θ1 ≦ 76 [degrees]. Further, a second end (leading end with respect to the tire rotation direction) crosses each of the inclined main grooves 323 the tire equatorial plane CL and is another one of the inclined main grooves 323 connected. In addition, there is an angle δ2, the inclined main grooves 323 with the small inclined grooves 324 at the second end of the inclined main grooves 323 within a range of 37 [degrees] ≦ θ2 ≦ 57 [degrees]. In addition, the plurality of inclined main grooves forms 323 a zigzag middle groove extending along the tire circumferential direction on the tire equatorial plane CL. A groove width of each of the inclined main grooves 323 in a section constituting the middle groove, is not less than 2 mm and not more than 6 mm, and a groove depth in the same section is not less than 2 mm and not more than 6 mm.

The small inclined grooves 324 are inclined with respect to the tire circumferential direction in such a shape as to be aligned in a single direction in the tire circumferential direction and away from the tire equatorial plane CL. In addition, each of the plurality of minor inclined grooves cuts 324 two of the inclined main grooves 323 and both ends thereof terminate within the middle land portion 32 , It should be noted that each of the plurality of small inclined grooves 324 three or more of the inclined main grooves 323 can cut (not shown). In addition, the plurality of small inclined grooves 324 arranged in the tire circumferential direction at a predetermined pitch and is arranged alternately in the tire circumferential direction on both sides of the tire equatorial plane CL. Further, a distance D6 from the tire equatorial plane CL to the end on the inside in the tire width direction of the small inclined grooves 324 and the distance DE from the tire equatorial plane CL to the ground contact edge T of the tire has a relationship such that 0.05 ≦ D6 / DE ≦ 0.25. Further, a distance D7 from the tire equatorial plane CL to the end on the outside in the tire width direction of the small inclined grooves 324 and the distance DE from the tire equatorial plane CL to the ground contact edge T of the tire has a relationship such that 0.25 ≦ D7 / DE ≦ 0.45.

The left and the right shoulder bridge section 31 and 33 each have a plurality of lug grooves 311 respectively. 331 and narrow circumferential grooves 316 respectively. 333 on.

Each of the lug grooves 311 ( 331 ) has a first end with the main circumferential groove 21 ( 22 ) and a second end that crosses the ground contact edge T of the tire, and extends in the tire width direction. In addition, each of the lug grooves 311 ( 331 ) over the main circumferential groove 21 ( 22 ) with the inclined main grooves 323 connected. That is, the lug grooves 311 ( 331 ) and the inclined main grooves 323 have opposite opening portions, which are the main circumferential groove 21 ( 22 ) point.

In addition, in the modification example 5 of 7 the narrow circumferential grooves 316 and 333 straight shaped narrow grooves extending in the tire circumferential direction. A groove width of the narrow circumferential grooves 316 and 333 is set to be within a range of not less than 2 mm and not more than 4 mm. In addition, a groove depth of the narrow circumferential grooves 316 and 333 is set to be within a range of not less than 2 mm and not more than 4 mm.

In addition, a ground contact width D_ce in the middle region corresponds to a width of the middle web section 32 from the left and right main circumferential grooves 21 and 22 is divided (see 7 ). Furthermore, groove surfaces of the inclined main grooves 323 and the small inclined grooves 324 in a groove area within the ground contact width D_ce of the central region and the groove surfaces of the main circumferential grooves 21 and 22 are not included. On the other hand, the groove area of the left and right circumferential main grooves 21 and 22 and the groove surfaces of the inclined main grooves 323 and the small inclined grooves 324 enclosed in a total groove area in the ground contact patch of the tire. On this basis, a groove area ratio S_ce within the ground contact width D_ce in the center area of the ground contact patch of the tire and the total groove area ratio S_t in the ground contact patch of the tire are calculated and optimized to be within the above-described ranges.

In the modification example 5 of 7 As described above, the middle land portion 32 the inclined main grooves 323 and the little inclined grooves 324 which extend from the vicinity of the tire equatorial plane CL to the outside in the tire width direction. Therefore, the water drainage performance and the snow drainage performance of the tire are improved. Such a configuration is advantageous because dry steering stability and steering stability on snow are improved. In addition, cut the small inclined grooves 324 at least two of the inclined main grooves 323 and are configured so that both ends thereof are within the middle land portion 32 end up. Furthermore, the inclined main grooves 323 and the little inclined grooves 324 alternately arranged in the tire circumferential direction. Therefore, the rigidity of the tread portion is maintained. As a result, the steering stability on snow can be improved while suitably securing the dry steering stability.

In addition, in the modification example 5 of 7 the middle bridge section 32 and the left and right shoulder land sections 31 and 33 each of the plurality of slats 312 * . 322 * and 332 * on. Furthermore, all of the slats 312 * in the shoulder land section 31 are arranged in the inner side area, three-dimensional slats and all of the slats 332 * in the shoulder land section 33 are arranged in the outer side region, are two-dimensional slats. As a result, not less than 90% of the fins exist 312 * and 322 * in the inside area of three-dimensional slats and not less than 90% of the slats 332 * and 322 * in the outer side area consist of two-dimensional slats.

It should be noted that the slats 322 * in the middle bridge section 32 are arranged, two-dimensional slats or three-dimensional slats can be. Alternatively, a combination of two-dimensional slats and three-dimensional slats can be arranged. In a configuration where all of the slats 322 * in the middle bridge section 32 are two-dimensional fins, the steering stability of the tire on snow is improved. In contrast, in a configuration where all slats 322 * Three-dimensional fins are the dry steering stability of the tire improved.

In addition, the shoulder land section becomes 31 in the inside area of the upper inside rubber 151_in * formed (rubber hardnesses H1_in * and H2_in * satisfy 68 ≤ H1_in * ≤ 78 and 65 ≤ H2_in * ≤ 75) and the shoulder land portion 33 in the outer side area is made of the upper outer side rubber 151_out * formed (rubber hardness H1_out * and H2_out * meet 65 ≤ H1_out * ≤ 75 and 62 ≤ H2_out * ≤ 72). Therefore, the rigidity of the shoulder land portion becomes 31 set high in the inside area and the rigidity of the shoulder bar section 33 in the outside area is set low.

It should be noted that the middle bridge section 32 from the upper inside rubber 151_in * can be formed and also from the upper outer side rubber 151_out * can be formed (not shown). In a configuration where the middle land portion 32 from the upper inside rubber 151_in * is formed, the dry steering stability of the tire is improved. In contrast, in a configuration where the middle land portion 32 from the upper outer side rubber 151_out * which improves steering stability of the tire on snow.

In addition, in the modification example 5 of 7 the pneumatic tire 1B a display indicative of a mounting direction on a vehicle, wherein the inner side portion is located on the inner side in the vehicle width direction. Typical high performance vehicles use a configuration that sets a large negative camber angle. Here, as described above, the rigidity of the first land portion 31 high and therefore can by such mounting of the pneumatic tire 1B in that the first web section 31 is on the inside in the vehicle width direction, the rigidity of the tread portion are maintained at a high level. As a result, the durability performance of the tire at high speed is improved.

Effects B

As described above, the pneumatic tire 1B the plurality of main circumferential grooves 21 to 23 extending in the tire circumferential direction and the plurality of land portions 31 to 34 coming from the main circumferential grooves 21 to 23 divided and formed in the tread portion on (see 2 ). In addition, each of the plurality of web portions 31 to 34 the majority of lamellae 312 * until respectively 342 * on. In addition, not less than 90% of the fins exist 312 * and 322 * , which are arranged in the inside area, of three-dimensional slats and not less than 90% of the slats 332 * and 342 * , which are arranged in the outer side area, consist of two-dimensional slats. In addition, the tread portion has an upper rubber 151 and a lower rubber 152 on. A rubber hardness H1_in * at -10 ° C and a rubber hardness H2_in * at 20 ° C of the upper rubber 151_in * in the inside area and a rubber hardness H1_out * at -10 ° C and a rubber hardness H2_out * at 20 ° C of the upper rubber 151_out * in the outer side area, such relationships are H1_in *> H1_out * and H2_in *> H2_out * (see 1 ).

In the above-described configuration, the three-dimensional fins are 312 * and 322 * arranged in the inner side area and the two-dimensional slats 332 * and 342 * are arranged in the outer side area (see 2 ). Therefore, the rigidity in the inside area is set high and the rigidity in the outside area is set low. In addition, the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * in the outside area have such relationships that H1_in *> H1_out * and H2_in *> H2_out *. Therefore, the rigidity in the inside area is set high, and the rigidity in the outside area is set low. Thus, there is a synergistic increase in inside-side stiffness and a synergistic decrease in outside-side stiffness. As a result, when wearing the pneumatic tire 1B is mounted on a vehicle such that the inner side portion is located on an inner side in the vehicle width direction, the inner side portion greatly contributes to improving the dry steering stability, and the outer side portion greatly contributes to improving the steering stability on snow. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are largely achieved.

In addition, in the configuration described above, as described above, the rigidity in the inner side area is high, and therefore, when the pneumatic tire 1B is mounted on a vehicle with a large camber angle, that the inner side portion is located on the inside in the vehicle width direction, the rigidity of the tread portion to a large extent maintained. Such a configuration is advantageous because the durability performance of the tire is improved at high speed. In addition, in the above-described mounting state, the ground contact length of the tire on the inside in the vehicle width direction increases. Here, as described above, the rigidity in the inner side area is high, which is advantageous because the drying performance of the tire is further improved.

In addition, fulfill in the pneumatic tire 1B the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * in the outside area the conditions: 68 ≦ H1_in * ≤ 78, 65 ≤ H2_in * ≤ 75, 65 ≤ H1_out * ≤ 75 and 62 ≤ H2_out * ≤ 72 and 3 ≤ H1_in * - H1_out * ≤ 10 and 3 ≤ H2_in * - H2_out * ≤ 10. In the above described Configuration, the ranges of the rubber hardnesses H1_in * and H2_in * in the inside area and the rubber hardnesses H1_out * and H2_out * in the outside area and the rubber hardness difference between the inside area and the outside area are suitably set. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, in the pneumatic tire 1B the sipe density D_in * of the inner side region and the sipe density D_out * of the outer side region have such a relationship that 1.2 ≦ D_out * / D_in * ≦ 2.0. With such a configuration, a ratio D_out * / D_in * of the louver density D_out * of the outside area to the louver density D_in * of the inside area is appropriately set. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, in the pneumatic tire 1B the groove area ratio S_in * of the inner side area and the groove area ratio S_out * of the outer side area in the ground contact patch of the tire are such that 1.2 ≦ S_out * / S_in * ≦ 2.0, and the total groove area ratio S_t in the ground contact patch of the tire is within Range of 0.25 ≤ S - T ≤ 0.38. In the above-described configuration, the ratio S_in * / S_out * of the groove area ratio S_in * in the inside area to the groove area ratio S_out * in the outside area, and the total groove area ratio S_t are set appropriately. Such a configuration is advantageous because both dry steering stability and steering stability of the tire on snow are achieved to a greater extent.

In addition, the pneumatic tire points 1B lug grooves 311 and 341 open to the bottom contact edge T of the tire in the inner side region and the outer side region, respectively (see 2 ). In addition, a groove width W1 * of the lug grooves 311 of the inner side portion and a groove width W2 * of the lug grooves 341 of the outside area has a relationship such that 0.5 mm ≦ W2 * - W1 * ≦ 2.0 mm. Such a configuration is advantageous because the lug grooves 311 of the inner side portion are narrow, and therefore the dry steering stability and the durability performance of the tire are improved at high speed. Furthermore, such a configuration is advantageous because the lug grooves 341 of the outside area are wide and therefore the performance of the tire on snow is improved.

In addition, in the pneumatic tire 1B a groove depth Hd1 * of the lug grooves 311 of the inner side portion and a groove depth Hd2 * of the lug grooves 341 of the outside portion has a relationship such that 1.0 mm ≦ Hd2 * - Hd1 * ≦ 3.0 mm. Such a configuration is advantageous because the lug grooves 311 of the inner side portion are shallow, and therefore, in particular, the durability performance of the tire at high speed is improved. Furthermore, such a configuration is advantageous because the lug grooves 341 of the outside area are deep and therefore the performance of the tire on snow is improved.

In addition, the pneumatic tire points 1B three of the main circumferential grooves 21 to 23 and four of the bridge sections 31 to 34 in the tread section (see 6 ). In addition, the ground contact width of the first land portion 31 at the bottom contact edge T in the inner side region greater than the ground contact width of the fourth web portion 34 at the ground contact edge T in the outer side area. In addition, the first web section 31 the majority of inclined grooves 313 that are inclined with respect to the tire circumferential direction, the plurality of first lug grooves 314_a and 314_b that run in the tire width direction from the outside of the ground contact patch of the tire, so that they with the inclined grooves 313 are connected, and the plurality of second lug grooves 315_a to 315_c that run in the tire width direction so that they are the inclined grooves 313 and the main circumferential groove 21 connect, up. In addition, three or more of the first lug grooves 314_a and 314_b with one of the inclined grooves 313 connected.

In the configuration described above, the first land portion 31 in the inside area a wider structure and the first bridge section 31 has the plurality of inclined grooves 313 , the majority of first lug grooves 314_a and 314_b and the plurality of second lug grooves 315_a to 315_c on. Therefore, the rigidity of this wide first land portion becomes 31 reduces and the Wasserabflusseigenschaften the first web section 31 be ensured. Because three or more of the first lug grooves 314_a and 314_b with one of the inclined grooves 313 In addition, the water drainage properties and the snow traction properties of the first land portion become 31 improved. Such a configuration is advantageous because dry performance, wet performance and snow performance of the tire can be achieved.

In addition, the pneumatic tire points 1B the one middle bridge section 32 that of the left and right outer major circumferential grooves 21 and 22 divided and formed in the central area, on (see 7 ). The middle bridge section 32 has the plurality of inclined main grooves 323 and the plurality of small inclined grooves 324 , in the Tire circumferential direction are arranged on. Furthermore, the majority of inclined main grooves runs 323 with respect to the tire circumferential direction, are each inclined in such a shape that they are aligned in a single direction in the tire circumferential direction and move away from a tire equatorial plane CL. In addition, a first end of each of the plurality of inclined main grooves 323 with the left or right outermost circumferential main groove 21 or 22 connected. In addition, the majority of inclined main grooves 323 alternately arranged in the tire circumferential direction on both sides of the tire equatorial plane CL. Furthermore, the plurality of small inclined grooves runs 324 with respect to the tire circumferential direction, are each inclined in such a shape that they are aligned in a single direction in the tire circumferential direction and move away from a tire equatorial plane CL. In addition, each of the plurality of minor inclined grooves cuts 324 two of the inclined main grooves 323 and 323 and both ends thereof terminate within the middle land portion 32 , In addition, the plurality of small inclined grooves 324 alternately arranged in the tire circumferential direction on both sides of the tire equatorial plane CL.

In the configuration described above, the middle land portion 32 the inclined main grooves 323 and the little inclined grooves 324 which extend from the vicinity of the tire equatorial plane CL to the outside in the tire width direction. Therefore, the water drainage performance and the snow drainage performance of the tire are improved. Such a configuration is advantageous because dry steering stability and steering stability on snow are improved.

In addition, the pneumatic tire points 1B the indicator on which the mounting direction (see 2 ) on a vehicle, wherein the inside area is on the inside in the vehicle width direction. In the configuration described above, the inner side region with the high rigidity is disposed on the vehicle width direction inner side, and the low rigidity outer side region is disposed on the vehicle widthwise outer side. Such a configuration is advantageous because the inner side area greatly contributes to dry steering stability, the outer side area greatly contributes to the steering stability on snow, and both dry steering stability and steering stability of the tire on snow are largely achieved.

The pneumatic tire 1B has a display that specifies a mounting orientation on a vehicle, wherein a camber angle δ (not shown) is in a range -4 ° ≤ δ ≤ 0 °. Such a configuration is advantageous because functions of the inner side portion having the high rigidity suitably exhibit and the durability performance of the tire at high speed is effectively improved.

Example B

9 FIG. 12 is a table showing the performance test results of pneumatic tires according to Embodiment 2 of the present invention.

• (1) Bei den Bewertungen der Trockenlenkstabilität wurde das Testfahrzeug, an dem die Luftreifen montiert waren, mit einer Geschwindigkeit von 60 km/h bis 240 km/h auf einer flachen Teststrecke gefahren. Dann führte der Testfahrer eine sensorische Bewertung hinsichtlich des Lenkens bei Fahrspurwechsel und Kurvenfahren und Stabilität beim Vorwärtsfahren durch. Die Ergebnisse der Bewertungen wurden indiziert und der Indexwert des Luftreifens des Beispiels des Stands der Technik 3 wurde als Standardpunktwert (100) verwendet. Höhere Punktebewertungen waren bevorzugt.
• (2) Bei den Bewertungen der Lenkstabilität auf Schnee wurde das Testfahrzeug, an dem die Luftreifen montiert waren, mit einer Geschwindigkeit von 40 km/h auf einem Handlingparcours in einer Schneeteststreckeneinrichtung gefahren und der Testfahrer führte eine sensorische Bewertung durch. Die Ergebnisse der Bewertungen wurden indiziert und der Indexwert des Luftreifens des Beispiels des Stands der Technik 3 wurde als Standardpunktwert (100) verwendet. Höhere Punktebewertungen waren bevorzugt.
• (3) Bei den Bewertungen der Haltbarkeitsleistung bei hoher Geschwindigkeit wurde ein Trommelprüfgerät für Innenräume verwendet. Der Sturzwinkel δ wurde auf δ = –3 [Grad] eingestellt. Die Fahrtstrecke bis zum Versagen des Reifens wurde unter den folgenden Testbedingungen gemessen: Fahrgeschwindigkeit = 300 km/h. Durch Indizieren der Messergebnisse wurden Bewertungen durchgeführt, wobei das Beispiel des Stands der Technik 3 als Standardpunktwert (100) diente. Bei diesen Bewertungen waren höhere Punktwerte bevorzugt.

In the performance tests, a plurality of different pneumatic tires were evaluated for (1) dry steering stability, (2) steering stability on snow, and (3) high-speed durability performance (see 9 ). In these performance tests, pneumatic tires with a tire size of 235 / 45R19 were mounted on rims with a rim size of 19 × 8J, filled to an air pressure of 250 kPa and loaded with 85% of a "load capacity" according to ETRTO. A saloon with four-wheel drive and a displacement of 3.0 l was used as a test vehicle.

• (1) In the dry steering stability evaluations, the test vehicle on which the pneumatic tires were mounted was run at a speed of 60 km / h to 240 km / h on a flat test track. Then, the test driver made a sensory evaluation for steering in lane change and cornering, and stability in forward driving. The results of the evaluations were indexed and the index value of the pneumatic tire of the prior art example 3 was used as the standard score (100). Higher scores were preferred.
• (2) In the steering stability evaluations on snow, the test vehicle on which the pneumatic tires were mounted was driven at a speed of 40 km / h on a handling course in a snow test track device, and the test driver conducted a sensory evaluation. The results of the evaluations were indexed and the index value of the pneumatic tire of the prior art example 3 was used as the standard score (100). Higher scores were preferred.
• (3) The high-speed durability ratings used an interior drum tester. The camber angle δ was set to δ = -3 [degrees]. The distance to the failure of the tire was measured under the following test conditions: Driving speed = 300 km / h. Evaluations were made by indexing the measurement results, with the example of prior art 3 serving as the standard score (100). For these ratings, higher scores were preferred.

The pneumatic tires 1B Embodiments 12 to 18 had the structure of 1 and the tread pattern of 2 and had three main circumferential grooves 21 to 23 and four bridge sections 31 to 34 in the tread section. In addition, all of the lamellae existed 312 * and 322 * in the first bridge section 31 and the second land portion 32 in the inside area of three-dimensional slats and all of the slats 332 * and 342 * in the third bridge section 33 and the fourth bridge section 34 in the outer side area consisted of two-dimensional lamellae. Furthermore, the rubber hardnesses were H1_in * and H2_in * of the upper rubber 151_in * in the inner side area larger than the rubber hardnesses H1_out * and H2_out * of the upper rubber 151_out * in the outer side area (H1_in *> H1_out * and H2_in *> H2_out *). In addition, the relationship between the sipe density D_in * of the inside area and the sipe density D_out * of the outside area was set. In addition, the groove area ratio S_in * in the inner side area and the groove area ratio S_out * in the outer side area of the ground contact patch of the tire were set by the groove area or the arrangement pitch of the lug grooves of the land portions 31 to 34 was set.

The pneumatic tire 1B of Embodiment 19, the tread pattern of FIG 6 on. Furthermore, the boundary was between the upper rubber 151_in * the inner side region and the upper rubber 151_out * of the outside area on the first circumferential main groove 21 , In addition, all of the lamellae existed 312 * of the first bridge section 31 from three-dimensional slats and all of the slats 322 * to 342 * of the second land section 32 to the fourth bridge section 34 consisted of the two-dimensional lamellae. The pneumatic tire 1B of Embodiment 20, the tread pattern of FIG 7 on. Furthermore, the boundary was between the upper rubber 151_in * the inner side region and the upper rubber 151_out * of the outside area on the tire equatorial plane CL. In addition, all of the lamellae existed 312 * and 322 * in the area on the side of the inner side portion which has been delimited from the tire equatorial plane CL, of three-dimensional fins and all of the fins 332 * and 322 * in the area on the side of the outside area consisted of two-dimensional lamellae.

The pneumatic tire of the prior art example 3 had three main circumferential grooves and four land portions in the tread portion. In addition, all of the fins in each of the land portions were two-dimensional fins. Further, the rubber hardnesses H1_in * and H2_in * of the upper rubber of the land portions in the inner side area were larger than the rubber hardnesses H1_out * and H2_out * of the upper rubber of the land portions in the outer side area. In addition, the sipe density D_in * of the inner side portion was smaller than the sipe density D_out * of the outer side portion.

As the test results show, the pneumatic tires are 1B of Embodiments 12 to 20 improves the dry steering stability and the steering stability on snow of the tires as compared with the pneumatic tire of the prior art example (see FIG 9 ). In addition, in a comparison of Embodiments 12 and 13, it becomes apparent that both the dry steering stability and the steering stability of the tire on snow are achieved because the rubber hardness difference between the inside and outside regions is properly adjusted. In addition, it is apparent from a comparison of Embodiments 12, 14 and 15 that both the dry steering stability and the steering stability of the tire are achieved on snow, because the ratio D_in * / D_out * of the sipe density D_in * of the inner side region to the sipe density D_out * of the outer side region is suitable is set and the ratio S_in * / S_out * of the groove area ratio S_in * in the inner side area to the groove area ratio S_out * in the outer side area and the total groove area ratio S_t are set appropriately. Moreover, comparing Embodiments 12 and 16 to 18, it becomes clear that the durability performance of the tire is improved at high speed because the relationship between the groove width W1 * and the groove depth Hd1 * of the lug grooves in the inner side region and the groove width W2 * and the groove depth Hd2 * of the lug grooves in the outside area is set appropriately.

LIST OF REFERENCE NUMBERS

1A, 1B

tire

11

bead

12

bead fillers

13

carcass

14

belt layer

141, 142

belt plies

15

Tread rubber

151

Upper rubber

151_in, 151_in *

Upper inside rubber

151_out, 151_out *

Upper outside rubber

152

Lower rubber

16

Sidewall rubber

21-24

Main circumferential groove

25

Narrow circumferential groove

31-35

web sections

311, 321, 331, 341, 351

lug grooves

312, 322, 332, 342, 352, 312 *, 322 *, 332 *, 342 *, 352 *

lamella

313

Inclined groove

314

First lug groove

315

Second lug groove

316, 333

Narrow circumferential groove

323

Inclined main groove

324

Small inclined groove

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2010-6108 A [0003]
• JP 3894743 [0036]
• JP 4316452 [0037]

Cited non-patent literature

• JIS-K6263 [0031]

Claims (14)

A pneumatic tire having a plurality of circumferential main circumferential grooves and a plurality of land portions partitioned and formed by the major circumferential grooves in a tread portion, wherein when an area corresponding to 35% of a straightened width of a tread pattern from a first tread edge is called an inner side area, and an area corresponding to 35% of a straightened width of a tread pattern from a second tread edge is called an outer side area, the plurality of land portions each having a plurality of sipes, not less than 90% of the sipes arranged in the inner side region, consist of two-dimensional sipes and not less than 90% of the sipes arranged in the outer side region consist of three-dimensional sipes, the tread portion comprises an upper rubber and a lower rubber, and a rubber hardness H1 in at -10 ° C and a rubber hardness H2_in at 20 ° C of the top rubber in the inside area and a rubber hardness H1_out at -10 ° C and a rubber hardness H2_out at 20 ° C of the top rubber in the outside area have such relationships that H1_in <H1_out and H2_in <H2_out. A pneumatic tire according to claim 1, wherein the rubber hardnesses H1_in and H2_in in the inside area and the rubber hardnesses H1_out and H2_out in the outside area satisfy the following conditions: 65 ≦ H1_in ≦ 75, 62 ≦ H2_in ≦ 72, 68 ≦ H1_out ≦ 78 and 65 ≦ H2_out ≦ 75, and 3 ≦ H1_out-H1_in ≦ 10 and 3 ≦ H2_out-H2_in ≦ 10. A pneumatic tire according to claim 1 or 2, wherein a sipe density D_in of the inner side portion and a sipe density D_out of the outer side portion have such a relationship that 1.2 ≤ D_in / D_out ≤ 2.0. A pneumatic tire according to any one of claims 1 to 3, wherein a groove area ratio S_in of the inner side area and a groove area ratio S_out of the outer side area in a ground contact patch of the tire have a relationship such that 1.2 ≦ S_in / S_out ≦ 2.0, and a total groove area ratio S_t in FIG Ground contact area of the tire is within a range of 0.25 ≤ S_t ≤ 0.38. A pneumatic tire having a plurality of circumferential main circumferential grooves and a plurality of land portions partitioned and formed by the major circumferential grooves in a tread portion, wherein when an area corresponding to 35% of a straightened width of a tread pattern from a first tread edge is called an inner side area, and an area corresponding to 35% of a straightened width of a tread pattern from a second tread edge is called an outer side area, the plurality of land portions each having a plurality of sipes, not less than 90% of the sipes arranged in the inner side region, consist of three-dimensional sipes and not less than 90% of the sipes arranged in the outer side region consist of two-dimensional sipes, the tread portion comprises an upper rubber and a lower rubber, and a rubber hardness H1_in * at -10 ° C. and a rubber hardness H2_in * at 20 ° C. of the upper rubber in the inner side region and a rubber hardness H1_out * at -10 ° C. and a rubber hardness H2_out * at 20 ° C. of the upper rubber in the outer side region have such relationships in that H1_in *> H1_out * and H2_in *> H2_out *. The pneumatic tire according to claim 5, wherein the inner side rubber hardnesses H1_in * and H2_in * and the outer side rubber hardnesses H1_out * and H2_out * satisfy the following relationships: 68 ≦ H1_in * ≦ 78, 65 ≦ H2_in * ≦ 75, 65 ≦ H1_out * ≦ 75 and 62 ≤ H2_out * ≤ 72, and 3 ≤ H1_in * - H1_out * ≤ 10 and 3 ≤ H2_in * - H2_out * ≤ 10. A pneumatic tire according to claim 5 or 6, wherein a sipe density D_in * of the inner side portion and a sipe density D_out * of the outer side portion have such a relationship that 1.2 ≦ D_out * / D_in * ≦ 2.0. A pneumatic tire according to any one of claims 5 to 7, wherein a groove area ratio S_in * of the inner side area and a groove area ratio Sout * of the outer side area in a ground contact patch of the tire have a relationship such that 1.2 ≦ S_out * / S_in * ≦ 2.0, and Total groove area ratio S_t in the ground contact patch of the tire is within a range of 0.25 ≦ S_t ≦ 0.38. A pneumatic tire according to any one of claims 5 to 8, wherein each of the inner side portion and the outer side portion has lug grooves open to a ground contact edge of the tire, and a groove width W1 * of the lug grooves in the inner side region and a groove width W2 * of the lug grooves in the outer side region have such a relationship have that 0.5 mm ≤ W2 * - W1 * ≤ 2.0 mm. A pneumatic tire according to any one of claims 5 to 9, wherein each of the inner side portion and the outer side portion has lug grooves open to a ground contact edge of the tire, and a groove depth Hd1 * of the lug grooves in the inner side region and a groove depth Hd2 * of the lug grooves in the outer side region have such a relationship have that 1.0 mm ≤ Hd2 * - Hd1 * ≤ 3.0 mm. A pneumatic tire according to any one of claims 1 to 10, having three of the major circumferential grooves and four of the land portions in a tread portion, wherein a ground contact width of the land portions at the bottom contact edge of the inner side portion is larger than a ground contact width of the land portions at the bottom contact edge of the outer side portion, the land portions in the inner side region have a plurality of inclined grooves inclined with respect to the tire circumferential direction, a plurality of first race grooves extending in the tire width direction from an outer side of the ground contact surface of the tire so as to be connected to the inclined grooves, and a plurality of second lug grooves extending in the tire width direction so as to connect the inclined grooves and the main circumferential grooves, and, not less than three of the first lug grooves are connected to one of the inclined grooves. A pneumatic tire according to any one of claims 1 to 10, wherein When the left and right main circumferential grooves located outermost in the tire width direction are referred to as outermost circumferential main grooves, a region on an inner side in the tire width direction of the tread portion defined by groove center lines of the left and right outermost circumferential main grooves is referred to as the central region and left and right regions on outer sides in the tire width direction are referred to as shoulder regions, a single middle land portion divided and formed by the left and right outermost circumferential main grooves is arranged in the central area and the middle land portion has a plurality of inclined main grooves and a plurality of small inclined grooves arranged in the tire circumferential direction; the plurality of inclined main grooves with respect to the tire circumferential direction are each inclined in such a form as to be aligned in a single direction in the tire circumferential direction and away from a tire equatorial plane, a first end of each of the plurality of inclined main grooves with the left or right outermost circumferential main grooves is connected, and the plurality of inclined main grooves is arranged alternately in the tire circumferential direction on both sides of the tire equatorial plane, and the plurality of small inclined grooves with respect to the tire circumferential direction are each inclined in such a shape as to be aligned in a single direction in the tire circumferential direction and away from a tire equatorial plane, each of the plurality of small inclined grooves intersects two of the main inclined grooves and both ends thereof within the central land portion, and the plurality of small inclined grooves are alternately arranged in the tire circumferential direction on both sides of the tire equatorial plane. A pneumatic tire according to any one of claims 1 to 12, which has a display indicating a mounting direction on a vehicle, wherein the inner side portion is located on an inner side in the vehicle width direction. A pneumatic tire according to claim 13, comprising a display defining a mounting orientation on a vehicle, wherein a camber angle δ (not shown) is in a range -4 ° ≤ δ ≤ 0 °.

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